2052 Crohn's Disease and Rare Renal Extra-Intestinal Manifestations: Two Case Reports

Abstract

INTRODUCTION: Crohn's Disease (CD) diagnosis is usually based on the presence of gastrointestinal symptoms and findings. Extra-intestinal manifestations (EIMs) occur in up to 50% of patients with CD. We present two cases of rare renal EIM associated with CD activity. CASE DESCRIPTION/METHODS: Case 1: 31 yo white male w/ ileal-colonic CD diagnosed in 2014 presents with 6 weeks of diarrhea, abdominal pain, fatigue, and frothy urine. 3 years prior he developed biopsy proven acute interstitial nephritis from mesalamine which resolved with cessation and steroid taper. He is not on any medications. Laboratory analysis reveals: BUN 40 mg/dL, Cr 6.06 mg/dL, GFR of 13 mL/min, CRP 4 mg/dL, urinalysis with 25 RBCs and no leukocytes, urine protein/creatinine ratio (Pr/Cr) of 1.6, and negative serologies for HIV, HCV, HBV, ANA, ANCA. Complement levels were normal. Renal biopsy shows tubular interstitial nephritis (TIN) with lymphocytic T-cell infiltrate with interstitial fibrosis and tubular atrophy. Random colon biopsies show mild active pan-colitis with non-necrotizing granulomas and normal terminal ileum. He is treated with a slow prednisone taper and adalimumab, but does not have renal recovery resulting in a kidney transplant. Immunosuppression includes tacrolimus, mycophenolate mofetil, and prednisone. Follow-up CD monitoring reveals no symptoms and negative fecal calprotectin. Case 2: 21 yo healthy white female presents with 3 months of watery diarrhea, abdominal pain, and fevers up to 103 F. She is on no medications. Laboratory analysis reveals: Hgb 8.4 g/dL, normal BUN, and a Cr of 1.8 rising to 2.6 mg/dL. Urinalysis with 4 RBCs, 39 leukocytes with negative culture, positive urine eosinophils, Pr/Cr 0.36, CRP of 17 mg/dL, and negative serologies as in case 1. Colonoscopy reveals moderate pan-colitis with non-necrotizing granulomas. Renal biopsy reveals granulomatous interstitial nephritis. She improves with a prolonged steroid taper but has persistent but mild colitis on evaluation. She has no renal recovery but does not require dialysis. DISCUSSION: Renal EIMs of CD are rare. Most commonly they include nephrolithiasis in 28% CD, medication adverse effects, amyloidosis, as well as CD activity correlated TIN and glomerulonephritis. There is no standard treatment for TIN, but a prolonged steroid taper, MMF, cyclosporine, and anti-TNF therapy may be attempted for CD and renal recovery. Both cases reveal renal recovery may not occur with significant immunosuppression and transplant may be required.